Well, evidently I'm in the minority here, but my vote is for shiny new parchment door cups and armrests.
The reason being, the rest of the Bronco is restored. In design, as you undoubtedly know, there's a point at which an idea is taken too far, and the overall design aesthetic is compromised. If you go into an old home that has been gutted and remodeled, but they salvaged the nice old wood kitchen windows and shutters, then people say, "Oh, what a wonderful home, and look! They kept these beautiful old windows and shutters with the nice patina!" But if the windows and shutters remain original, and so does the old stove and cabinets and floor, then people say, "Huh. They didn't finish this room. It looks a little tired and worn." So, for your Bronco, I vote new parchment door cups and arm rests, because I think they'll go better with the rest of your restored Bronco, and then this wonderful artwork will really pop! The art will be more of a focal piece and design element.
TL; DR: New white parchment will make the art pop more.